Husbands and wives whose marriages are coming apart or who have already gone through the pain of divorce have as their patron St. Helen (or Helena). After more than 20 years of marriage, Helen’s husband divorced her to make a politically advantageous match with a young woman who was a member of Rome’s imperial family.

St. Helen was born in the town of Drepanum in northern Turkey; her father and mother were innkeepers. It was while she was working at her parents’ inn that Helen met a Roman soldier named Constantius Chlorus, a man whose origins were as humble as Helen’s; Constantius’ father was a goatherd; his mother was the daughter of a slave who had been liberated by his master. Constantius was an ambitious man who saw in the military an opportunity to rise above his low birth status.

The couple married in 270. Two years later, they were in Serbia at Constantius’ new post in the town of Nish. There, on Feb. 27, 272, Helen gave birth to a son. They named the boy Constantine.

We have no documents to tell us what happened to the family between the year of Constantine’s birth and 288, the year Constantius was appointed governor of Dalmatia. At some point during that interval, Constantius had won the confidence of the co-emperors, Diocletian and Maximian. Imperial patronage meant that Constantius was poised for great things, and in 292, Maximian selected Constantius to administer the provinces of Gaul, Spain and Britain. As a sign of special favor, the emperor urged Constantius to divorce Helen and marry Flavia Maximiana Theodora, Maximian’s stepdaughter. To sweeten the offer, Maximian arranged for 20-year-old Constantine to finish his military training by fighting Rome’s enemies in Egypt.

These were heady days for Constantius and Constantine, but it must have been a wretched time for Helen. After 22 years of family life, she found herself discarded by her husband and deprived of the company of her son.

We do not know what happened to Helen after Constantius divorced her, with one exception: We know that at some point during those lonely years, Helen converted to Christianity. Then, after the death of Constantius in 306, Constantine and his mother were reunited, and Constantine’s army proclaimed him emperor. While he was on the march to Rome to defend his title against a rival, Constantine had a vision of a cross of light inscribed with the words, “In this sign, conquer.” Constantine ordered a new military standard — a cross surmounted by the Greek monogram Chi-Rho, the first two letters in the name Christ. Led by the cross, Constantine’s army went into battle at the Milvian Bridge outside Rome where he conquered his rival, as the vision had promised.

A year later, Constantine published the Edict of Milan, which put an end to the persecution of the Church and guaranteed toleration to Christians throughout the Roman Empire. To console his mother for all those unhappy years after her divorce, Constantine showered honors on Helen. He granted her the imperial title Augusta, renamed her birthplace Helenopolis and had coins struck bearing her image. In Rome, Constantine gave Helen as her residence the Sessorian Palace, part of which — including Helen’s private chapel — survives today as the Basilica of the Holy Cross in Jerusalem.

St. Helen is also the patron of converts to the Catholic faith and of archaeologists. Her feast day is August 18.

Craughwell is the author of more than 30 books, including “Saints Behaving Badly” and “This Saint Will Change Your Life.”